| Title | Efficiency of Scaling Inhibitors in Geothermal Fluids at High Temperature and High Pressure |
|---|---|
| Authors | Harsh KUMAR VERMA, Dhruv MAKWANA, Jayesh BELLANI |
| Year | 2020 |
| Conference | World Geothermal Congress |
| Keywords | Geothermal Energy, Geothermal Fluids, Scaling Inhibitors, Environment-friendly |
| Abstract | This paper is aimed at reviewing the results obtained by the assessment of the performance of scaling inhibitors and their efficiency in geothermal wells at high temperature and high pressure (HPHT) conditions. As a fluid is pumped out of a geothermal reservoir it suffers a drastic change in the temperature and pressure. Since the reservoir fluid or water constitutes of a number of dissolved minerals, these minerals suffer a shift in the equilibrium and hence precipitation takes place. This commonly known phenomenon of ‘scaling’ affects the reservoir properties and hence the efficiency of the geothermal wells by hindering the flow of fluid through pipelines, valves, etc. A special class of compounds known as scaling inhibitors is used widely to reduce the scaling during the process of extraction of geothermal fluids. But the problem does not solve here as the scaling inhibitors that are used at such high temperature and pressure conditions along with high salinity in the reservoirs are not actually tested for use at such vigorous conditions which results in the decrease in their efficiency. Hence to test these scaling inhibitors a qualitative and quantitative approach was made. The methods used for the same were: (a) jar or bottle test which is carried out in a reactor at static conditions, and, (b) the dynamic tube blocking test (TBT). Inhibitors used were phosphonates, polyacrylates, polyaspartates and a carboxymethylated polysaccharide. Scales were CaCO3, CaSO4 and BaSO4. It was found that the efficiency of the scaling inhibitors decreased at HPHT conditions in the static batch test. The flow rate and capillary geometry also affected the scaling inhibition in TBT. |